1. Technical Field
The present invention relates to an AC direct drive lamp including a leakage current protection circuit, including an input stage configured to receive external power, a rectification circuit configured to rectify the external power received from the input stage, a control module electrically connected to the output stage of the rectification circuit and configured to sense and control the state of at least one of the rectification circuit, a switch module, and a light source, the switch module connected between the input stage and the control module in a feedback form and configured to switch on/off depending on a predetermined condition, and the light source electrically connected to the control module and configured to radiate light when power is applied.
2. Description of the Related Art
In a conventional LED lamp, as shown in FIG. 1A, an AC direct drive (or embedded type) lamp in which external power 120 is connected to one end 121 of an electrode of a lamp 130 has been implemented in an insulating drive type. In contrast, as shown in FIG. 1B, in a recent LED lamp, an AC direct drive (or embedded type) lamp in which external power 120 is connected to both ends 231 and 232 of the electrodes of a lamp 230 has been implemented in a non-insulating type.
Referring to FIG. 2, in the case of the AC direct drive lamp of a non-insulating type, a drive control module operates only when both ends 231 and 232 of a lamp 230 are normally connected before power 210 is applied. However, when one end 231 of the lamp 130 is connected to the power and the other end 232 of the lamp 130 comes into contact with a user 240 in the state in which the power 210 has been applied, there is a problem in that the user may be subject to a danger of a momentary electric shock because the leakage current flows into the ground GND.
Furthermore, a common mechanical type switch, such as a contact type push method, is used to prevent an electric shock attributable to the leakage current when a user replaces or repairs a lamp. However, when power is applied to the lamp, a driving voltage of about 1 kV is first applied for 0.2 second. If a product to which the mechanical type switch has been applied is used for a long time, power of a high voltage continues to be applied to a metal plate within the mechanical type switch. Accordingly, the mechanical type switch that needs to be an open state physically enters a short-circuit state temporarily. As a result, there is a problem in that a user is subject to a danger of a momentary electric shock.
Furthermore, the mechanical type switch has a problem in that a defect may occur because moisture may be penetrated between switches because waterproofing, that is, the most important issue of an LED lamp, cannot be applied to the mechanical type switch. Accordingly, research has been carried out on various methods for implementing an AC direct drive lamp, which block an instant overvoltage and prevent the leakage current.